Bit-brace jaws.



PATENTED DEC. 20, 1904 J. P. BARTHOLOMEW.

BIT BRAUE JAWS.

APPLIOATION FILED MAR. 1, 1904.

N0 MODEL 0 I I 11411. 4 n f. r a %E 1 @f m i M UNTTED STATES Patented December 20, 1904.

PATENT FFICE.

JOSEPH PECK BARTHOLOMEW', OF BRISTOL, CONNECTICUT, ASSIGNOR TO THE STANLEY RULE & LEVEL COMPANY, OF NEW BRITAIN, CONNECTI- CUT, A CORPORATION OF CONNECTICUT.

BlT-BRAGE JAWS.

SPECIFICATION forming part of Letters Patent No. 777,657, dated. December 20, 1904.

Application filed March 1, 1904. Serial No. 196,014.

To all whom it perry concern:

Be it known that I, J osnrn PEOK BARIHOL- oMnw, a citizen of the United States, residing at Bristol, in the county of Hartford, State of Connecticut, have invented certain new and useful Improvements in Bit-Brace Jaws, of which the following is a full, clear, and exact description.

My invention relates to bit-braces, and particularly to an improved construction of the tool-gripping portion thereof.

The invention consists mainly in connecting two jaws by a spring in such a manner that the open ends of the jaws will be correctly po- 5 sitioned to receive the tool when the usual operating-sleeve is moved in a direction to allow said jaws to open, the spring serving to normally cause said jaws to open for the purpose specified. When the tool is inserted, the jaws are drawn together in opposition to the tendency of the spring by any well-known means for example, by the action of the well-known operating-sleeve common in bit-braces.

The particular details of the preferred con- 5 struction are illustrated in the accompanying sheet of drawings, in which Figure 1 is a side elevation of a pair of jaws embodying the improvements of my invention, the same being shown as gripping a por- 3 tion of a tool, the operating-sleeve being shown in dotted outline. Fig. 2 is a longitudinal section of the jaws, showing the grooves and the spring located therein, the parts being in the position which they would normally assume 55 if removed from the operating-sleeve. Fig. 3 is a side elevation of the jaws. Fig. 4: is a view of the inside of one of the jaws, showing the spring at the upper end in section. Fig. 5 is a lower end view of the jaws as they ap- 4 pear in Fig. 2.

1 and 2 are jaws having suitable toolgripping portions 8 and 4 at the interior walls thereof. 5 is a spring which connects both of said jaws 1 and 2 and is adapted to'automatically retract or open the free ends of said jaws to facilitate the entrance of a tool. Were the jaws removed from the bit-brace, they would normally assume the position shown in Fig. 2. Communicating grooves or channels are formed in the upper outer ends of the 5 jaws, which grooves preferably continue along the outer side walls of said jaws, the function of said grooves being to receive and protect the spring 5. As shown, there are two holes,

one in each of said jaws, into which the ends of the spring 5 project, the extreme ends of said spring 5 being bent or turned back, as at 6 and 7, so as to retain said spring securely in place. In the preferred form of my invention I prefer to further secure the spring in place by indenting or swaging down a portion of the metal on one or both sides of each groove in the outer surface. The swaged or drawn-down portions are indicated at 8 9 and the same engage the spring 5.

In operation it will be seen the spring tends to normally open the jaws. The free ends of the jaws are drawn together by an operatingsleeve which takes against the beveled free ends of said jaws after the usual manner. 7 When the jaws are assembled in a bit-brace, the spring is protected from coming in contact with the sleeve, and hence is not worn. The method of assembling is simple and the finished article durable and effective. The spring 5 not only connects the jaws so that they will be positioned correctly relatively to the operating-sleeve, but the jaws are also prevented from being twisted out of place relatively to the spring. Furthermore, the invention has the advantages of economy of construction, durability, and efficiency of operation.

In the preferred form the ends 6 7 of the spring 5 are bent back, so as to form hooks 5 facing the bow in the spring, thus securely inclosing those portions of the jaws 1 2 contained between the spring to prevent any possible accidental disengagement of the parts.

I also preferably provide recesses in the inner 9 wall of the jaws 1 2, in which the ends 6 Tot the spring lie, so as to be substantially flush with the surface of the jaw, thus preventing any possible interference with the shank of the tool.

represents the shank of the tool as it would appear in place in the jaws.

11 illustrates in dotted outline the usual operating-sleeve of a bit-brace, showing its position relatively to the jaws 1 2.

What I claim is p 1. In a device of the character described, a pair of independent jaws having tool-receiving cavities in their adjacent outer ends, grooves across the inner ends of said jaws on the outer surfaces thereof, said grooves being in the same plane, a perforation in each of said jaws intermediate the length thereof a bowed spring located outside of said jaws, the bow of said spring being located in the grooves at the inner ends thereof, angular bands at the ends of said spring, the extreme ends of said spring being projected into said intermediate perforations.

2. In a device of the character described, a pair of independent jaws having tool-receiving cavities in their adjacent outer ends, grooves across the inner ends of said jaws on the outer surfaces thereof, said grooves being in the same plane, a perforation in each of said jaws intermediate the length thereof, a bowed spring located outside of said'jaws, the bow of said spring being located in the grooves at the inner ends thereof, angular bends at the ends of said spring, the extreme ends of said spring being projected into said intermediate perforations, channels in the outer sides of said jaws extending longitudinally thereof and connecting said perforations with said end grooves.

8. In a device of the character described, a pair of independent jaws having tool-receiving cavities in their adjacent outer ends, grooves across the inner ends of said jaws on the outer surfaces thereof said grooves being in the same plane, a bowed spring seated in said grooves and outside of said jaws the ends of said spring bearing against the sides of said jaws and means to secure the ends of said springs to said jaws intermediate the length of the latter.

Signed at Bristol, Connecticut, this 27th day of February, 1904.

JOSEPH PECK BARTHOLOMEW.

Witnesses:

W. J. WORAM, V. G. HOFFMAN. 

